This research seeks to exploit a new technique to study the biophysics and biochemistry of "cell-cell recognition," especially involving cellular components of the immune system. The new technique, dubbed the evanescent wave, supported lipid monolayer (EWSM) technique, replaces one cell of a cell-cell pair by a lipid monolayer a solid support such as a microscope slide. When specific molecules that link a cell to the monolayer are fluorescent, then the linker molecules that are within about 700/Angstroms of the monolayer membrane are stimulated to emit when a laser beam undergoes total external reflection in the microscope slide. Using this technique, information on the motion and distribution of molecules involved in specific cell-membrane, monolayer membrane binding and triggering can be observed with a fluorescence microscope, for molecules such as lipid haptens, antibodies, viral proteins, and histocompatibility antigens. The unique information obtainable indicates that the EWSM technique can be used to guide biochemical experiments such as the identification and isolation of cell membrane receptors, especially the elusive T-cell receptor. In such experiments, selected cross-linking agents are included in the lipid monolayer so as to bond only to those cell plasma membrane components that bind specifically to the monolayer.